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+libtracefs(3)
+=============
+
+NAME
+----
+tracefs_print_init, tracefs_print_close, tracefs_printf, tracefs_vprintf -
+Open, close and write formated strings in the trace buffer.
+
+SYNOPSIS
+--------
+[verse]
+--
+*#include <tracefs.h>*
+
+int *tracefs_print_init*(struct tracefs_instance pass:[*]_instance_);
+int *tracefs_printf*(struct tracefs_instance pass:[*]_instance_, const char pass:[*]_fmt_, _..._);
+int *tracefs_vprintf*(struct tracefs_instance pass:[*]_instance_, const char pass:[*]_fmt_, va_list _ap_);
+void *tracefs_print_close*(struct tracefs_instance pass:[*]_instance_);
+
+--
+
+DESCRIPTION
+-----------
+Set of functions to write formated strings in the trace buffer.
+See Documentation/trace/ftrace.rst from the Linux kernel tree for more information about writing
+data from user space in the trace buffer. All these APIs have _instance_ as a first argument. If
+NULL is passed as _instance_, the top trace instance is used.
+
+The *tracefs_print_init()* function initializes the library for writing into the trace buffer of
+the selected _instance_. It is not mandatory to call this API before writing strings, any of
+the printf APIs will call it automatically, if the library is not yet initialized. But calling
+*tracefs_print_init()* in advance will speed up the writing.
+
+The *tracefs_printf()* function writes a formatted string in the trace buffer of the selected
+_instance_. The _fmt_ argument is a string in printf format, followed by variable arguments _..._.
+
+The *tracefs_vprintf()* function writes a formatted string in the trace buffer of the selected
+_instance_. The _fmt_ argument is a string in printf format, followed by list _ap_ of arguments.
+
+The *tracefs_print_close()* function closes the resources, used by the library for writing in
+the trace buffer of the selected instance.
+
+RETURN VALUE
+------------
+The *tracefs_print_init()*, *tracefs_printf()*, and *tracefs_vprintf()* functions return 0 if
+the operation is successful, or -1 in case of an error.
+
+EXAMPLE
+-------
+[source,c]
+--
+#include <tracefs.h>
+
+if (tracefs_print_init(NULL) < 0) {
+ /* Failed to initialize the library for writing in the trace buffer of the top trace instance */
+}
+
+void foo_print(char *format, ...)
+{
+ va_list ap;
+ va_start(ap, format);
+ if (tracefs_vprintf(NULL, format, ap) < 0) {
+ /* Failed to print in the trace buffer */
+ }
+ va_end(ap);
+}
+
+void foo_print_string(char *message)
+{
+ if (tracefs_printf(NULL, "Message from user space: %s", message) < 0) {
+ /* Failed to print in the trace buffer */
+ }
+}
+
+tracefs_print_close();
+--
+FILES
+-----
+[verse]
+--
+*tracefs.h*
+ Header file to include in order to have access to the library APIs.
+*-ltracefs*
+ Linker switch to add when building a program that uses the library.
+--
+
+SEE ALSO
+--------
+*libtracefs*(3),
+*libtraceevent*(3),
+*trace-cmd*(1),
+Documentation/trace/ftrace.rst from the Linux kernel tree
+
+AUTHOR
+------
+[verse]
+--
+*Steven Rostedt* <rostedt@goodmis.org>
+*Tzvetomir Stoyanov* <tz.stoyanov@gmail.com>
+--
+REPORTING BUGS
+--------------
+Report bugs to <linux-trace-devel@vger.kernel.org>
+
+LICENSE
+-------
+libtracefs is Free Software licensed under the GNU LGPL 2.1
+
+RESOURCES
+---------
+https://git.kernel.org/pub/scm/libs/libtrace/libtracefs.git/
+
+COPYING
+-------
+Copyright \(C) 2021 VMware, Inc. Free use of this software is granted under
+the terms of the GNU Public License (GPL).